@MattMoose
It can't. You need some stuff in php, python, etc to do that.
@jamesb thanks. I really want to completely separate content (text & links) from style (html and CSS). I want placeholders in the html file to display specific bits from, say, a separate text/CSV file.
This quest is proving more trouble than it's worth, so I'll stick to bashing the html file around in an editor for now. But it's a direction. Cheers